The present invention relates to a self-venting hollow window frame structure have and improved venting system.
Providing weep opening to drain water from the interior of hollow frames such as window frames is common practice. Normally, such systems incorporate a one-way valve to permit the escape of water from within the hollow frame while prohibiting the inflow of air from the outside. In these system the inside of the frame is at a pressure corresponding to the pressure on the interior of the building in which the frame is mounted.
Attention is directed to U.S. Pat. No. 3,314,201 issued Apr. 15, 1967; U.S. Pat. No. 3,410,027 issued Nov. 12, 1968; U.S. Pat. No. 3,503,169 issued Mar. 31, 1970; U.S. Pat. No. 3,636,660 issued Jan. 25, 1972; U.S Pat. No. 3,849,938 issued Nov. 26, 1938; U.S. Pat. No. 3,858,357 issued Jan. 7, 1975 to Silvernail; U.S. Pat. No. 5,787,659 issued Aug. 4, 1998; U.S. Pat. No. 5,822,934 issued Oct. 20, 1998 and U.S. Pat. No. 5,887,387 issued Mar. 30, 1999 provide examples of drainage systems for hollow frames that control air flow from the exterior of the building toward the interior of the building, many of which use one way valves for such control. The majority of the patented systems position the one way valve on an outside wall of the frame, U.S. Pat. No. 3,314,201 places the valve in an intermediate wall and employs surface tension to hold the valve closed. U.S. Pat. No. 3,849,938 provides a system of draining the frame of a louvered window also places the flap valve on in intermediate wall.
U.S. Pat. No. 5,044,121 equalizes air pressure on the inside of the frame with that on the exterior of the building to under high wind conditions to avoid drawing up and accumulation of water in the sash by providing vent holes communicating with the outside at the top of the sash connecting the interior of the sash with the outside pressure and drain holes at the bottom of the sash also communicating with the outside so that the internal pressure around the frame is the same as the outside pressure.
U.S. Pat. No. 3,845,599 issued Nov. 5, 1974 uses the level of water to be drained to open and close a valve leading from the hollow interior of the frame to the building interior side of the frame. The valve only closes if the level in which the float valve is contained increases to a certain level, however a hydraulic seal is maintained at all times between the outside of the building and the inside U.S. Pat. No. 4,003,171 issued Jan. 18, 1997 also uses water in the hollow frame to open a valve to permit water to drain to the outside.
U.S. Pat. No. 4,475,324 issued Oct. 9, 1984 discloses a specific valve for a vent opening through a window frame or the like and connecting the interior of the building with the exterior.
It is an object of the invention to provide an improved venting and draining system for hollow window frame or the like structures.
Broadly the present invention relates to a frame structure incorporating an improved venting system said window frame structure including a plurality hollow frame pieces forming inside passages in said frame structure, drain holes interconnecting said inside passages to form a drain passage leading through said inside passages to a drain hole through said fame connecting said inside passage to outside of said frame, the improvement comprising a one way valve mounted in an inner wall of said frame in a position to interconnect said inside passage with the interior of a building in which said window frame is mounted and oriented to impair flow into said building from said inside passage when air pressure in said inside passage is higher than air pressure in said interior of said building and to permit flow from said interior of said building to said inside passage when air pressure in said interior is higher than air pressure in said inside passage.
Preferably said valve is a flapper type valve.
Preferably said valve is constructed to be slightly open when air pressures on opposites sides of said valve are essentially the same.